The processing of silver halide photographic materials, e.g., silver halide color photographic materials, generally comprises as basic steps a color developing step, a desilvering step and an image stabilizing step, such as a washing step. In the color developing step, the color developing agent reacts with silver halide to generate imagewise dyes and developed silver. In the desilvering step, the developed silver generated in the color developing step is converted into the silver salt by the oxidation (bleaching) with a bleaching agent having an oxidizing action, and further removed from the light-sensitive layer together with the silver halide remaining unused therein through the reaction with a fixing agent capable of forming a soluble silver salt. In another way, the conversion into silver salts by oxidation and their removal are carried out at one step by the use of a bleach-fix bath. The image stabilizing step is a process of controlling the image layer atmosphere so as to secure the long-term stability of images formed. Therein, the washing with water or the processing with the combination of water and an image stabilizing bath, a stabilizing bath instead of water or so on is carried out.
Each of the processing steps, excepting a washing step, is effected using a water solution containing at least one processing chemical (which is referred to as a processing solution). Since each processing solution has a relatively low concentration, the way in which the processing solutions are produced by a maker of processing chemicals in a condition that they can be used as they are, transported to processing laboratories and stored therein is generally unsuitable from the viewpoint of economy, storage space or working efficiency.
Hitherto, this problem has been solved by two methods. In one of these methods, the powdery processing chemicals to constitute the desired processing solution are mixed in the ratio corresponding to the composition of the processing solution, the powdery mixture obtained is wrapped up and supplied to processing laboratories as the so-called solid processing chemicals. And the desired processing solution is prepared in each processing laboratory by dissolving the solid processing chemical in a proper amount of water. In the other method, concentrated liquid chemical is prepared by dissolving processing chemicals as constituents of the desired processing solution in high concentrations, charged into containers and supplied to processing laboratories. And the desired processing solution is prepared in each processing laboratory by diluting the concentrated prepared liquid chemical with water or the like to a definite concentration. The former method is described in U.S. Pat. Nos. 2,843,484 and 2,846,308, Canadian Patent 831,928, and so on; while the latter method, specifically the concentrated prepared liquid chemicals for color development, is described in U.S. Pat. Nos. 3,574,619, 3,647,461 and 3,814,606, and British laid-open patent application 2,016,723. Which method has an advantage over the other depends on the scale of a processing laboratory. Small-scale processing laboratories, such as the so-called mini laboratories, micro laboratories or over-the-counter laboratories, which have lately increased in number, are generally in a situation that they have neither proficient technical expert nor full-scale incidental facilities. Under such a working condition, the liquid processing chemicals which can be easily mixed with cold water and require neither hot water supply system nor stirring equipment are preferable to the solid processing chemicals, such as powdery, granular or tabular processing chemicals, which require rather complicate working to render the handling difficult and further need a stirring equipment as well as a hot water supply system. Therefore, concentrated prepared liquid chemicals have come to be prevailingly employed in small-scale processing laboratories.
However, the liquid processing chemicals have a defect that their components are subject to aerial oxidation and some components thereof are reactive to one another. Therefore, certain measures have been taken. For instance, each liquid chemical is divided into two or more parts for the purpose of preventing the reaction between components to ensure long-term storage stability, and stored in separate containers slightly pervious to oxygen with the intention of protecting each part against aerial oxidation. In the case of a color developer, the stability of which is regarded as especially important, the liquid processing chemical divided into three parts, specifically the alkali agent part, the color developing agent part and the preservative (e.g., hydroxylamine) part, is usually employed.
On the other hand, containers usable for storing liquid processing chemicals and protecting them from aerial oxidation have been investigated. As containers that enable almost perfect prevention of aerial oxidation, glass containers have so far been used, but they are inconvenient for handling because of their fragility. Therefore, containers made of a composite material, which is formed by laminating a plastic material slightly pervious to oxygen and a plastic material inert toward development-processing solutions, have also been employed. However, they have drawbacks of being expensive and undesirable for preservation of the environment because they are lacking in recycling suitability.
From the viewpoint of environmental protection, it is desirable for the containers to be recyclable, and so it is required for them to be made of a single material. As examples of a single-component plastic material recyclable and slightly pervious to oxygen, mention may be made of polyester resins and nylon resins. However, these resins are lacking in chemically sufficient stability to development-processing chemicals having strong alkalinity, so that their being used in practice causes problems. Accordingly, plastic materials having stability to development-processing solutions, being recyclable and enabling the container formation with a single-component material are limited practically to olefin resins, such as polyethylene and polypropylene. However, these resins have a weak point that they cannot prevent aerial oxidation because of their high perviousness to oxygen, so that there is a drawback to their application to color development processing chemical compositions although they are practical as the container material for bleach compositions and fixer compositions.
And what is even worse, the polyolefin resins, particularly polyethylene, have a drawback of generating color stains that have their roots in developing agents. The color developers for color photosensitive materials are generally p-phenylenediamine derivatives. Of such derivatives, 4-amino-3-methyl-N-ethyl-N-(.beta.-hydroxyalkyl)anilines (wherein the hydroxyalkyl moiety contains 2-4 carbon atoms) and acid salts thereof have strong developing activity, and so they are prevailingly used for color negative films, coupler-in-developer-type color photosensitive materials and so on. When they are charged into a polyethylene container, those color developing agents not only suffer deterioration due to aerial oxidation but also penetrate into the inner part of the container wall to color the container brown, in contrast to many other developing agents of similar type, such as acid salts of 4-amino-3-methyl-N-ethyl-N-(.beta.-methanesulfoamidoethyl)aniline. On the other hand, the recycling of the thus colored polyethylene as a container material and for other uses has turned out to be subject to serious restrictions. The coloration caused in the container material has a nature of not allowing the removal by washing.
Such being the case, the particularly desired color developer composition is a color developer composition that is charged in a container made up of a single material, enabling stable storage of the contents, free from coloration and recyclable at a low cost, contains at least one developing agent selected from the group consisting of 4-amino-3-methyl-N-ethyl-N-(.beta.-hydroxyethyl)aniline, 4-amino-3-methyl-N-ethyl-N-(.beta.-hydroxypropyl)aniline, 4-amino-3-methyl-N-ethyl-N-(.beta.-hydroxybutyl)aniline and the salts thereof, and adjusted to pH 10-12.
Additionally, the term "recycle" as used herein means that the used containers are regenerated as new containers through a recycling process, but does not refer to the reuse as repeated use of the same container.